package com.ruoyi.test.interceptor;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * 功能：实现访问资源的拦截
 *
 * @author 陈剑波
 */
public class MyInterceptor extends HandlerInterceptorAdapter implements HandlerInterceptor {

    public static final String LAST_PAGE = "com.alibaba.lastPage";

    /**
     * 在业务处理器处理请求之前被调用
     * 如果返回false
     * 从当前的拦截器往回执行所有拦截器的afterCompletion(),再退出拦截器链
     * 如果返回true
     * 执行下一个拦截器,直到所有的拦截器都执行完毕
     * 再执行被拦截的Controller
     * 然后进入拦截器链,
     * 从最后一个拦截器往回执行所有的postHandle()
     * 接着再从最后一个拦截器往回执行所有的afterCompletion()
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        /*
        System.out.println(new Throwable().getStackTrace()[0] +
                "==============执行顺序: 1、preHandle================\n" +
                "uri: " + request.getRequestURI() + "\n" +
                "params: " + request.getQueryString()
        );
         */
        if(1 < 2) {
            return true;
        }
        HttpSession session = request.getSession();
        if(session.getAttribute("currentPerson") == null){
            System.out.println("用户未登录");
            return false;
        }
        //System.out.println("会话过期时间：" + request.getSession().getMaxInactiveInterval());
        System.out.println("用户已登录：" +
                session.getAttribute("currentPerson"));
        return true;
    }

    /**
     * 在业务处理器处理请求执行完成后,生成视图之前执行的动作
     * 可在mv中加入数据，比如当前时间
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView mv) throws Exception {
        /*
        System.out.println(new Throwable().getStackTrace()[0] +
                "==============执行顺序: 2、postHandle================\n" +
                "uri: " + request.getRequestURI() + "\n" +
                "params: " + request.getQueryString() + "\n" +
                "handler: " + handler
        );
        */
    }

    /**
     * 在DispatcherServlet完全处理完请求后被调用,可用于清理资源等
     * <p>
     * 当有拦截器抛出异常时,会从当前拦截器往回执行所有的拦截器的afterCompletion()
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception e) throws Exception {
        /*
        System.out.println(new Throwable().getStackTrace()[0] +
                "==============执行顺序: 3、afterCompletion================\n" +
                "uri: " + request.getRequestURI() + "\n" +
                "params: " + request.getQueryString() + "\n" +
                "handler: " + handler
        );
       */
    }

}















